RFA: test C++ casts

[Fernando Nasser]

New tests are good.

Thanks.

Fernando

Jim Blandy wrote:
> 2002-08-21  Jim Blandy  <jimb@redhat.com>
> 
> 	* gdb.c++/casts.cc, gdb.c++/casts.exp: New test.
> 
> Index: gdb/testsuite/gdb.c++/casts.cc
> ===================================================================
> RCS file: gdb/testsuite/gdb.c++/casts.cc
> diff -N gdb/testsuite/gdb.c++/casts.cc
> *** gdb/testsuite/gdb.c++/casts.cc	1 Jan 1970 00:00:00 -0000
> --- gdb/testsuite/gdb.c++/casts.cc	21 Aug 2002 22:01:21 -0000
> ***************
> *** 0 ****
> --- 1,20 ----
> + struct A
> + {
> +   int a;
> +   A (int aa): a (aa) {}
> + };
> + 
> + struct B: public A
> + {
> +   int b;
> +   B (int aa, int bb): A (aa), b(bb) {}
> + };
> + 
> + int
> + main (int argc, char **argv)
> + {
> +   A *a = new B(42, 1729);
> +   B *b = (B *) a;
> + 
> +   return 0;  /* breakpoint spot: casts.exp: 1 */
> + }
> Index: gdb/testsuite/gdb.c++/casts.exp
> ===================================================================
> RCS file: gdb/testsuite/gdb.c++/casts.exp
> diff -N gdb/testsuite/gdb.c++/casts.exp
> *** gdb/testsuite/gdb.c++/casts.exp	1 Jan 1970 00:00:00 -0000
> --- gdb/testsuite/gdb.c++/casts.exp	21 Aug 2002 22:01:21 -0000
> ***************
> *** 0 ****
> --- 1,80 ----
> + # Copyright 2002 Free Software Foundation, Inc.
> + 
> + # This program is free software; you can redistribute it and/or modify
> + # it under the terms of the GNU General Public License as published by
> + # the Free Software Foundation; either version 2 of the License, or
> + # (at your option) any later version.
> + # 
> + # This program is distributed in the hope that it will be useful,
> + # but WITHOUT ANY WARRANTY; without even the implied warranty of
> + # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
> + # GNU General Public License for more details.
> + # 
> + # You should have received a copy of the GNU General Public License
> + # along with this program; if not, write to the Free Software
> + # Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  
> + 
> + # Please email any bugs, comments, and/or additions to this file to:
> + # bug-gdb@prep.ai.mit.edu
> + 
> + # This file is part of the gdb testsuite
> + 
> + # Test casting, especially between class types or pointer-to-class
> + # types.
> + 
> + # This file is part of the gdb testsuite
> + 
> + if $tracelevel then {
> +         strace $tracelevel
> +         }
> + 
> + #
> + # test running programs
> + #
> + 
> + set prms_id 0
> + set bug_id 0
> + 
> + if { [skip_cplus_tests] } { continue }
> + 
> + set testfile "casts"
> + set srcfile ${testfile}.cc
> + set binfile ${objdir}/${subdir}/${testfile}
> + 
> + if [get_compiler_info ${binfile} "c++"] {
> +     return -1;
> + }
> + 
> + if  { [gdb_compile "${srcdir}/${subdir}/${srcfile}" "${binfile}" executable {debug c++}] != "" } {
> +      gdb_suppress_entire_file "Testcase compile failed, so all tests in this file will automatically fail."
> + }
> + 
> + 
> + gdb_exit
> + gdb_start
> + gdb_reinitialize_dir $srcdir/$subdir
> + gdb_load ${binfile}
> + 
> + gdb_test "break [gdb_get_line_number "casts.exp: 1"]" \
> +     "Breakpoint.*at.* file .*" \
> +     ""
> + 
> + gdb_test "run" "Breakpoint .* at casts.cc" ""
> + 
> + # Casting a pointer to a base class to a pointer to a derived class
> + # should yield the entire derived class.  Until August 2002, GDB got
> + # the enclosing type on `(B *) a' wrong: while the value's static type
> + # was `B *', as it should be, the enclosing type (which is supposed to
> + # be the dynamic type) was `A *'.  It's senseless to have a static
> + # type derived from the dynamic type; it should be the other way
> + # 'round.  Dereferencing this oddly typed pointer yielded a value in
> + # which only the base class's members were initialized, since GDB uses
> + # the enclosing type to decide how many bytes to read.  Members from
> + # the derived class were garbage, from GDB's address space.
> + gdb_test "print * (B *) a" ".* = {<A> = {a = 42}, b = 1729}" \
> +     "cast base class pointer to derived class pointer"
> + 
> + # Check also that we get the same results from letting the compiler do
> + # the dereference.
> + gdb_test "print * b" ".* = {<A> = {a = 42}, b = 1729}" \
> +     "let compiler cast base class pointer to derived class pointer"
> 


-- 
Fernando Nasser
Red Hat Canada Ltd.                     E-Mail:  fnasser@redhat.com
2323 Yonge Street, Suite #300
Toronto, Ontario   M4P 2C9